Hey guys and girls out there I was working on my alternator issue on a 71 mercury cougar it seems not to be charging the battery. I have original harness hooked up to the voltage regulator. It has three wires that plug into the first three of the A the I and the F I believe and I don’t have anything running into the S on the voltage regulator which I believe is a stater do I need to have anything running to the stater? I guess is my question to have it charging the battery so would I run it from the voltage regulator to the back of the alternator to possibly charge battery. I was also thinking about running a one wire with a little bit more amperage alternator just to save the issues I was having so it would charge the battery directly, but I kind of wanted to figure out what the problem was before I fixed the problem by doing something else.
Legend,
Is your car a standard or an XR7? I am confused as to your wiring to the F,A and I circuits
Standards have 4 wires at the voltage regulator,
Standard Voltage regulator wiring
- F - Field Connected to the Alternators F post
- S - Stator Connected to the Alternators Stator Post
- A - Battery Connects to the Starter Solenoids Battery post
- I - Indicator Connects to the Alternator Light and the ignition switch
XR7 only have 3 wires at the voltage regulator
- F - Field Connected to the Alternators F post
- S - Stator - Connects to the Ammeter and the ignition switch, does NOT connect to the Alternators Stator post
- A - Battery Connects to the Starter Solenoids Battery post
- I - Indicator NOT USED in ammeter systems
As a quick test on the vehicle, disconnect the plug at the voltage regulator. Using a jumper wire with male connectors on both ends, place one end in the F terminal connector and the other end on the A connector. This effectively bypasses the voltage regulator and provides full excitation to the alternator. The voltage reading at the bat post should now read 15V. If it still reads only 12 V, then the alternator is suspect ( you should remove it and have a shop bench test it ) or the wires to/from the alternator and voltage regulator are suspect.
Good luck!
Coach Jack
Hey Coach,
Sorry to sound so confusing yesterday on the voltage regulator you’re right it goes Fsai
I do have the XR seven the top three are plugged into the harness from the regulator the FS in the A, but the is not connected to anything and on the back of the alternator was wondering does anything have to run from the stater?
Legend,
On an XR7, the alternator’s S post is NOT used however it may be used for an electric choke for the carburetor, however the S post will only put out 6 unrectified AC Volts. Note most aftermarket Electric chokes require 12 V DC.
Coach Jack